Victoria: Spring Heat: October 19th -22nd 2009

A huge change in the weather for the coming week with 850T jumping into the mid/high teens. The jump day is Monday with the winds shifting from SW to NW with Tuesday likely to see temperatures into the high 20s/low 30s. Could be a second burst of heat late in the week.

Looks like next to no rain in the sequence with upper highs dominating.

So what's the wind and humidity going to be like? Some warmth wouldn't be too bad especially with all that snow in the catchments, as longs as its not to windy. I take it we will have to wait for the next two highs to pass before we have a chance of any rain?

Certainly looks warmer, however it appears that we may have a few days of afternoon storms. Take GFS Stormcast with a grain of salt, however it' forecast for Wed/Thurs should raise a few eyebows (especially Jake!!)

Yes is looking like a bit of a warm period, as expected by several of us! (You know who you are... haha.)

Seems to me, that the patterns are changing in the extended model runs, but too early to say for sure. I will speculate more once a couple more models update this evening.

And Wes, I have never seen LI values at that negative range for my region!!!!! (below -11) I am so wishing to the weather gods that it holds, it would be so unstable, and GFS' data shown would be severe storm galore!!! But, I will speculate more with further tonights model updates. Certainly could be a few stormy days.

I mentioned a while ago (and have been saying at work), the 24th October would bring on much warmer weather. I would like to change that to Tuesday 20th and Friday 23rd of October Am I allowed to do that? hahaha

Massive pattern change ahead, we will literately go from winter to summer in 5 days.

Lows and front dive south, Highs move south and get much larger, strong fronts and rain bearing lows replaced with weak troughs, wind changes and the odd shower and thunderstorm.

Also will be very warm to hot, Much of Northern Vic will see a few days in a row above 30c going to be a big shock for many, but this heat is normal by mid late October though on some days pushing a bit on the extreme side.
Tuesday and more so Friday looking hot but Friday is a long way away.

The last 6 weeks have been great all the rain and cool, many have had loads of rain and many in better state at this time of the year than they have in last 5-8 13 years which is just great.

Shame its all drying off, tap is REALLY turning off, but had to happen sooner or later. I cant see a rain bearing system again for a few weeks and wouldnt be surprised if dont see 10mm in next 2 weeks or more.

Been a great 6 weeks and the rain has been great, was just hoping it would last a bit longer, the heat will be welcome though, just not the dry so much, but know a few that are looking forward to warmth and sun.

Storms next weak not very excited at all, might be some around but they will be weak and nothing great need more moisture and stronger dynamics, still early days but i am not excited by anything that i see just yet any way

GFS has gone completely stupid and those progged LIs and CAPE are proof of this. That model more or less has every day from Monday to Friday with low to mid 30s max temps in Melbourne and higher in the north. At first I was very, very worried by this but now that I have seen EC completely different and -11 LI and 3200 CAPE progged by GFS for Thursday in western VIC I am disregarding it.

Of course there will still be bursts of heat, and potentially low to mid 30s on the hot days in Melbourne but EC has the systems moving on and southerly changes moving in. The oceans to our south are still cold so even a weak cool change will be significant unlike what we see in the middle of summer.

LOL well that would be nice Andrew...

I think it is fair that the shallow trough coming through on Tuesday will cool the uppers a little and setup the late week system. I think there is the potential for scattered showers and thunderstorms come Saturday along that trough axis but a long way off. Could be a nice producer if the uppers remain cool.

But before that a couple of days near 30C for Melbourne.

Agree with that Karl.

It does look as if the potential is there for some reasonable surface moisture considering how warm the air mass is so some shower and thunderstorm development is certainly a possibility some time in the period. What GFS is saying though would be sending US storm chasers down to VIC to chase.

Anyway, whilst it would be nice for the wet weather to continue on indefinitely, some warmth/heat will also be very nice seeing we are not that far away from November, it has been a very cool spell lately. Also keeping in mind plants need sun and warmth to grow as well as water so too much more of this cool, cloudy weather and plant growth would actually start to fall back.

Hmm, I prefer the BoM's forecast atm. Don't mind the odd warmer day but the low 20's would be better. We have all summer for heat so it's not like we need it to come in a hurry? Particularly if the tap starts to turn off.

hmm my birthday is on the 22nd, any chance of a storm for me??

I would like the heat to come now but so longs we can attatch some moisture to the end of a fine spell and get some thundery rain activity developing, then it is all worth it. These transitional weeks between seasons are the killers for us. Lets hope that we can squeeze something.

Andrew I would agree, if US is right, then expect cantelope sized hail and destructive winds. But lets not get carried away

James we will work something for you...wish us luck

Off in model fairy land (i.e 7 days and beyond) but for next Saturday (the 23rd) GFS has a classic spring time front, hot ahead of it, cold behind it and a solid area of rain progged with it. If we can get a front like this to end the sequence expect a severe squall line with rain areas behind it. Still a very long way off but it is classic to get these sort of systems at this time of year.

GFS also hinting at a few storms around Friday but given that we are dealing here with a model that progs -11 LI values we might just have to wait on that one until we get a lot closer to the day. Just looking at the latest GFS there appears to be a slight downgrade in the intensity of heat with just Friday likely to get much above 15C 850T.

Just having a quick review of the models now. There is something troughy likely to brew IMO.

Wes, did you get my post about my YTD?

Just after a quick review of the models, I think we will see a trough develop around Tuesday onwards, triggering isolated afternoon showers and thunderstorms on most days. Activity should be restricted to mostly the ranges on Tuesday afternoon if any, but then Wednesday there should be a chance throughout, before scattered activity develops Thursday and Friday throughout, with the help of the next frontal system that Andrew mentions. Thats how I read it at the moment. Long way out, but I am certain there will be a few thunderstorms around the state from Tuesday or Wednesday.

Jake, got it mate!! You've done well in comparison to other areas.
As expected (or tipped by the gurus) GFS stormcast downgrades the LI's, but as you mentioned it wont be a dry week, however it wont result in a widespread rain band on the cool change Wed/Thurs.

Looks to me like this will be chiefly a north of divide/NSW/SA "heatwave". It has the potential to be warm/hot for the whole week towards the river but in the south only Tues and Thur look like having the potential to be warm/hot at this stage. Of course, a subtle shift in the location of the highs could change that.

EC has 850Ts approach 20C during the week in the northwest so could see the first 100F for the year, though more likely to fall just short. Melbourne has to be a very outside chance for the first 30C for the year.

Can't see anything other than a little drizzle following the first front, but Thur-Sat is looking interesting for showers/storms, though my current thoughts are that most of these will be in southerlies behind the surface trough and triggered in the mid levels.

BTW interesting to see 35C forecast for Perth today (was 32C yesterday), with a smattering of 42C in northern WA yesterday (42 deg at West Roebuck, Mandora, Bidyadanga, Fitzroy Crossing). Shows that the air mass is getting warm over there.

Yeah, whilst we've been hidden away in the cool, wet and cloudy weather for most of this Spring it's business as usual through the interior and in the NW of the country where our main source of heat is, at least the sudden and extreme heat outbreaks that we get.

Does look like a fair downgrade on and south of the ranges for the week although Thursday/Friday still looks like it could get very hot through the south as well but not all models are in agreement of this so still a bit up in the air of what the exact conditions will be. Looks like a decent chance of either storms and consistently warm to hot (mainly GFS scenario) or light rain/drizzle and mainly just mild to warm with the odd hotter day (mainly EC scenario with several days of southerlies later on in the period).

Growth is going to go crazy this week with the warm temperatures and good soil moisture.

Monday looks like a transitional day to me in Melbourne seabreeze may take the edge of the temp infact wouldnt suprise me if it dodnt go beyond 21c. Only 2 days that look warm down here are Tuesday and Friday but can be questionable especially Friday once again depending on cloud/seabreeze and rain as EC has 4mm for us Friday.

Yeah I have pencilled in a 32C for Friday but may have to take Tuesday back to 25C. The change in conditions will continue right up to the days with timing of wind changes the key.

Looking interesting late week, I suspect DJ is right, though those situations can be rather productive as the uppers cool and instability increase, with a little moisture, can cause scattered convection and even modest rain bands.

I just wonder if people have taken into account seabreezes. Am I correct in thinking that as the landmass warms up, seabreezes are likely to happen and as the bay and southern seas are still quite cool, the seabreeze may come in and really drop temps? The only thing that can stop that would be very strong northerly winds.

Just a thought, could be completely wrong!

Tony

Seabreezes will play a part Monday where the outer suburbs will start to be about 1-3C warmer than the city.

Tuesday will be a northerly drift day and a SW change later will push in and as you say be re-enforced as a seabreeze if it comes through earlier than expected reducing temps.

Transition weather!!

Latest GFS has Friday as the only day with a 30C likely. The rest of the week from Monday on looks like yo-yoing between low 20s and mid to high 20s for Melbourne depending on when the changes come through, sea breezes etc. Confidence increasing with the storm outlook, GFS at least has a large mass of high precipitable water moving in from the Bight as the week progresses and interestingly enough associated with the NW stream also bringing in the heat. In general, the air doesn't really dry out that much and it actually gets very humid as the warmer air moves in. Chuck in a trough which is likely to hover over northern VIC and we get the chance for storms from around Tuesday on, particularly on and north of the ranges.

Next Saturday sees that rather vigorous front back in the progs with cold air behind it colliding with the warm and humid air. Could be a very interesting week yet, perhaps the tap hasn't quite been turned off hard enough and is still a chance to keep dribbling.

Still a long way out though, things will change.

Yes and the Bom going for rain Sat morning so there is something in it...EC is hinting at it without going all out for it...